An integrated optical system includes a wavelength tunable optical source and a photonic integrated circuit (PIC). The PIC includes a set of spatial waveguide switches having an input optically coupled to the wavelength tunable optical source and a plurality of outputs. The PIC also includes an optical emitter having a plurality of inputs, each being coupled to a respective one of the plurality of outputs of the set of spatial waveguide switches, the optical emitter configured to produce at an output an optical beam having a wavelength dependent emission direction that changes as light is switched by the set of spatial waveguide switches such that the optical beam may be steered in two dimensions.

Disclosed herein is a transponder comprising a transmitter and a receiver. The transponder further comprises a receiver input amplifier, a bypass line, and a control unit configured for determining the performance of the transponder in relation to an OSNR related parameter, by controlling the transponder to generate a noise signal to be received by the receiver. The receiver input amplifier is operated to thereby cause ASE in the receiver input amplifier to facilitate the determination. A test signal is generated at the transmitter Said noise signal and said test signal, and/or one or more respective replicas thereof, are superimposed to form a combined signal to be received by said receiver to further facilitate determination of said performance related parameter based on said combined signal, wherein for generating said combined signal, said test signal is fed from the transmitter to the receiver by means of said bypass line.

Disclosed herein is a transponder comprising a transmitter and a receiver. The transponder further comprises a receiver input amplifier, a bypass line, and a control unit configured for determining the performance of the transponder in relation to an OSNR related parameter, by controlling the transponder to generate a noise signal to be received by the receiver. The receiver input amplifier is operated to thereby cause ASE in the receiver input amplifier to facilitate the determination. A test signal is generated at the transmitter Said noise signal and said test signal, and/or one or more respective replicas thereof, are superimposed to form a combined signal to be received by said receiver to further facilitate determination of said performance related parameter based on said combined signal, wherein for generating said combined signal, said test signal is fed from the transmitter to the receiver by means of said bypass line.

An optical transmitter includes: a modulator, square law detector, and a processor. The modulator generates an optical signal indicating transmission data. The square law detector detects an intensity of the optical signal using a photodetector and output first intensity data indicating the detected intensity. The processor calculates, based on the transmission data, an electric field of the optical signal generated by the modulator by using parameters pertaining to a state of the modulator. The processor calculates second intensity data indicating the intensity of the optical signal based on the calculated electric field. The processor updates the parameters so as to reduce a difference between the first intensity data and the second intensity data. The processor controls the state of the modulator based on the parameters.

A quantum communications system may include transmitter node, a receiver node, and a quantum communications channel coupling the transmitter node and receiver node. The transmitter node may be configured to co-propagate a first pulse for a quantum state and a second pulse to stabilize the quantum state through the quantum communications channel.

The present disclosure relates to the field of microwave and optoelectronic technologies, and in particular to an integrated microwave photon transceiving front-end for a phased array system, including: a ceramic substrate, on which a control integrated circuit, a silicon-based photonic integrated chip, a first amplifying chipset, a second amplifying chipset, and a microwave switch chipset are carried. The control integrated circuit is configured to control the silicon-based photonic integrated chip and the microwave switch chipset by means of an input control signal. The silicon-based photonic integrated chip is connected at one end with an input/output optical fiber, and at the other end with the first amplifying chipset and the second amplifying chipset. The two amplifying chipsets are connected to the microwave switch chipset respectively, and the microwave switch chipset is further connected with a phased array antenna.

A method for updating a non-linear look-up table, an apparatus for updating a non-linear look-up table, and an optical receiver. The method for updating a non-linear look-up table includes: performing suppression processing on residual linear ISI contained in an input look-up table in an iterative update process of a look-up table to obtain a processed look-up table. The method eliminates adverse effects of a residual linear ISI in real time during an iterative update process of a LUT, so that a generated LUT coefficient does not continue to diverge along an iteration process, which ensures stable operation of pre-compensating on nonlinearity of an optical transmitter device.

Optical systems, receivers, devices, and methods including a free space beam combining and polarization splitting prism to receive local oscillator light and optical signals in substantially parallel input paths that are in the same plane and output two orthogonally polarized beams in substantially parallel output paths that are substantially perpendicular to the plane of the input paths. Light in one of the incoming paths is reflected toward a combining surface that combines the local oscillator light and the optical signal. The combined beam then encounters a polarization splitting surface that splits the combined beam into two orthogonally polarized beams. One of the polarized beam may be reflected 90 degrees in plane and then both orthogonally polarized beams are reflected 90 degrees of out of plane to output each orthogonally polarized beam into substantially parallel optical output paths.

A distributed fiber sensing system may use an integrated coherent receiver. The integrated coherent receiver may include a planar lightwave circuit including various optical components.

A coherent transceiver includes a modulator, a receiver, a filter, a splitter, a detector, and a controller. The modulator modulates a data on the basis of laser light and outputs transmission light. The receiver receives reception light with same wavelength as the transmission light from input multiplexed light, on the basis of the laser light. The filter is arranged on an input stage of the receiver and includes a first port that inputs the multiplexed light, a filter body that transmits the reception light from the multiplexed light, and a second port that outputs the transmitted reception light. The splitter splits the transmission light travelling from the modulator and inputs the splitted transmission light. The detector detects a level of the splitted transmission light input. The controller adjusts a passband of the filter on the basis of the detected level.